This Crane Fly or Daddy Long Legs (possibly Tipula scripta) got into the house and I gave a try to getting its portrait on a white background. It is pleasantly surprising how many insects that I expect to fly away immediately do actually stay still through my white bowl session. The little knobbed structures sticking out at the sides of the body are the halteres, typical of all flies but more prominent in these large flies. They evolved from the hindwings and when in flight move in opposite directions as the wings and are involved in balancing and steering and contribute to the exquisite flying abilities in the group, although crane flies themselves are weak, wobbly fliers
From mid April up to October, you might come across this handsome hoverfly resting on leaves or feeding on flowers either close or away from water. This species is Helophilus pendulus, the commonest of its genus in the UK, distinguished by other species by the parallel yellow stripes in the thorax, black stripe on its face and the mainly yellow hind tibia. The genus Helophilus, which is a wasp mimic, is closely related to Eristalis, the droneflies, which are bee mimics. Both genera share a rat-tailed aquatic or semiaquatic larvae. I found this female sitting on a sage leaf after a light shower. She was cold and reluctant to fly, and with a bit of coaching, she climbed on the white bowl and let me take her portrait.
The little Woundwort Shieldbug Eysarcoris venustissimus might easily pass unnoticed in your garden. It frequents native plants such as Enchanters nightshade, Herb Robert and, mainly Hedge Woundwort, where it lays its eggs and the nymphs develop. It can also complete its life cycle in the widely planted Lamb's Ears. On close up, it is a beautiful insect, iridescent bronze/green and white, heavily speckled with black dots. Today, I found the first mating pair of the year, 10 days after the first ones emerged from overwintering.
I see lots of Philodromus spiders with missing legs, some of them with up four legs missing. They are - incredibly - able to walk, and presumably find enough food to stay alive. Many spider species have weak points in their legs, when in danger of being predated or otherwise attacked, they shed them, a phenomenom called autotomy. Spider autotomy has actually been shown to be a voluntary act, as anesthetised spiders would not shed their legs. For a spider, it is costly to lose a leg, as it might impair reproductive or fighting ability, or success at hunting, but it is a small price to pay when the alternative is to be eaten. And the best thing is that sometimes legs are not lost forever, as immature spiders maintain the ability to regenerate lost limbs in the next moult (although long lived spiders that moult when adult, like tarantulas, do keep that ability for life). The spider on the top shot, enjoying a juicy aphid a few days ago, has regenerated the middle pair of legs on the foreground: notice that they are thinner and shorter than the rest, and lack the colour pattern seen on the equivalent legs on the other side. Even in the Philodromus below, which has lost four legs and a palp, the apparent stumps of the missing legs are actually the miniature folded regenerated legs.
The sun shone in all its glory to end this most rainy April. Many insects came out of their temporary hiding places to dry out and enjoy the warmth. Some of these were Scarlet Lily Beetles. I wasn't sure if I had an infestation, as I had collected just a couple of adults in the last few weeks, but today I found 12, the first ones were a mating couple. As I found them I placed them in a plastic pot, and while I was carrying it I noticed a faint chirping call. I thought that there must be a nest nearby with calling chicks, but then I realized that the sound was actually coming from the pot: the disturbed Lily beetles were stridulating! when I touched them, they chirped repeatedly. You can watch this short clip of them in the pot, as I push them inside the pot, they chirp - I was trying to place the camera on the pot opening to improve the sound recording, but they kept climbing up the pot.
The first description of the stridulation of this beetle was written by the early entomologist René Antoine Ferchault de Réaumur in 1737:
when one holds it, it lets a little cry be heard, produced by the friction of its last abdominal segments against the elytra, the more one presses the elytra against the body, the louder it cries
More recent studies have confirmed this description, and also shown that stridulation is common in the Lily Beetle subfamily (Criocerinae). The stridulatory apparatus consists on a file on the last tergite - the dorsal end of the abdomen - made of microscopic parallel ribs, which are scraped by files of sharp denticles in the underside margins of the elytra. The sound is produced while the abdomen contracts, and these contractions can be amazingly rapid, up to 200 times per minute and is loud enough to be heard if the beetles are less than 30 cm from your ear. The high variability of the chirps and the situations in which they are produced suggest that this behaviour is a defence mechanism: the beetle will chirp if captured and the sound can startle the potential predator to release the beetle before swallowing it. In other beetle species chirping is used in intraspecific communication, with the lily beetle, is is yet another way of avoiding being eaten.
